The present invention relates to a push button construction useful for an electronic watch. In electronic watches, whether of the digital type or the analog type with hands driven by a stepping motor, it is necessary to have switches which enable the user of the watch to advance the hands for setting or to select the functions performed by the internal integrated circuit. In the past, such push buttons usually have a seal or gasket to minimize or prevent moisture or other contaminants from entering the watch where electronic components might be adversely affected.
Push buttons are well known in the art of electronic watches, of the type where a push button is held in place by a spring retaining member holding the push button in position by means of spring fingers around a groove in the stem, the button being sealed by an O-ring resilient gasket sliding within a tube in the watch case. Such constructions are shown in U.S. Pat. Nos. 4,031,341 issued June 21, 1977 and 4,023,002 issued May 10, 1977, both in the names of Paul Wuthrich and Frank Mascia and assigned to the assignee of the present application. It is also known to use the resilient gasket to perform a spring return function as well as sealing, as shown in U.S. Pat. No. 4,031,348 issued June 21, 1977 to Noel Eberhardt.
Constructions have also been shown for incorporating a recessed push button in the underside of the watch, rather than on the edge, when the button is used infrequently for setting the watch. Such a push button is shown in U.K. patent application No. GB 2086097A assigned to ETA S.A. Fabriques D'Ebauches. In this application, elaborate means are employed to retain the button, maintain electrical contact, and to keep the assembly as thin as possible, so as not to increase the thickness of the watch.
Simplicity of manufacture and a minimum number of parts are desirable in a push button assembly for a watch. It would be very desirable to provide an improved retention means for a sealed push button assembly, particularly useful in the back of a thin watch.
Accordingly, one object of the present invention is to provide an improved sealed push button assembly for an electronic watch.
Another object of the invention is to provide an improved push button assembly utilizing a minimum number of parts and providing ease of assembly.
Another object of the invention is to provide an improved push button retaining means for a recessed button in the back of a very thin electronic watch.